Zero Gravity SR Series Windscreen - Smoke 20-246A-02 Best optics of any windscreen on the market. All are fabricated using highly specialized blow molding techniques similar to those used to form aircraft canopies. The result is virtually distortion-free optics Made from the finest grade of 1/8in. acrylic plastic. Each windscreen is stretched as it is formed, a process which results in superior strength and flexibility.